Water treatment apparatus and components

ABSTRACT

A portable water treatment apparatus including: a pump, a coarse filter means, an adsorbent filter means, a fine filter means, a silver ion generator downstream of the pump and in series with the adsorbent filter and control means for controlling the operation of said first silver generator whereby said silver ion generator discharges silver ions into the water at a predetermined rate and in response to a predetermined flow rate, said control means including a flow switch.

TECHNICAL FIELD OF THE INVENTION

This invention relates to apparatus for the treatment of water for humanconsumption and the destruction or removal of bacteria and othermicro-organisms which are dangerous to health, and components for suchapparatus.

BACKGROUND ART

It is relatively well known that silver ions (Ag+) in measured doses aretoxic to lower life forms such as bacteria but are non-toxic to humans.In fact there is evidence available that silver provides significantbenefits to the functioning of the human body and offers particularbenefits to the immune system. Various types of apparatus are presentlyavailable for dosing water with silver ions in order to take advantageof the bactericide effects of silver and typically such apparatusesinclude a flow switch which activates a silver ion generator upon aperson turning on a tap for a glass of water. Generally, apparatuses ofthis type have been used only in reticulated water systems, for example,where town water is connected and is already relatively clean andreasonably safe.

The steady growth of tourism in outback areas has placed an undesirableburden on government authorities to provide safe drinking and bathingwater in such areas for the benefit of tourists and holiday makers.However, the provision of such facilities decreases the appeal of theoutback and the ability of tourists and holiday makers to camp wherethey like. Moreover any facilities provided could possibly be destroyedor rendered ineffective by vandals. Additionally there are many areaswhich are so little used and so remote that government authorities areunable to provide and maintain the necessary facilities particularly indeveloping nations and jungle areas. Furthermore, even if presentlyavailable apparatus were to be used in remote areas, in some cases theydo not control the growth of harmful bacteria downstream of theapparatus to a satisfactory extent.

One object of the present invention is to provide water treatmentapparatus which controls or at least inhibits the growth of harmfulbacteria downstream of the apparatus and which can be used in outbackareas and/or with reticulated water supplies to improve water quality orat least decrease the possibility of harmful bacteria being consumed.Another object is to provide portable water treatment apparatus whichwill allow holiday makers and others, especially those with four wheeldrive vehicles, to sterilise and filter water from streams, water holes,dams and the like thus converting it to potable water for drinking andwashing. Another object is to provide an improved flow switch which canbe used for activating a silver ion generator in water treatmentapparatus of the type herein described.

DISCLOSURE OF THE INVENTION

With the foregoing in view the invention in one aspect resides broadlyin portable water treatment apparatus including:

-   -   a base and a handle operatively connected to said base by which        a person may carry the apparatus;    -   pump means operatively mounted to said base, said pump means        including a water inlet and a water outlet;    -   coarse filter means upstream of said pump means for filtering        undesirably large solids from the water prior to entering said        water inlet and a flexible conduit connected to said coarse        filter means for providing a flow path for the water to said        coarse filter means;    -   adsorbent filter means downstream of said pump means for        removing undesirable odours, tastes and chemical pollutants such        as chlorine, trichloromethanes, herbicides, pesticides and the        like from the water;    -   fine filter means downstream of said pump means and in series        with said adsorbent filter means for removing organisms of the        protozoan group particularly amoeba, giardia, and        cryptospiridium from the water;    -   a first silver ion generator downstream of said pump means and        in series with said adsorbent filter means and said fine filter        means for releasing silver ions into water inflowing from said        pump outlet;    -   control means for controlling the operation of said first silver        ion generator whereby said silver ion generator discharges        silver ions into the water at a predetermined rate and in        response to a predetermined flow rate, said control means        including a flow switch;    -   flow regulating means downstream of said pump means and in        series with said adsorbent filter means, said fine filter means        and said first silver ion generator for regulating the rate of        flow of water from said pump outlet;    -   connection means for connecting a battery type power supply to        said pump means and/or said silver ion generator, and    -   cover means removably attached to said base means for covering        or at least partially covering said pump means, said coarse        filter means, said adsorbent filter means, said fine filter        means and said first silver ion generator. Preferably, the        portable water treatment apparatus also includes a second silver        ion generator downstream of said adsorbent filter means and said        fine filter means for releasing silver ions into the filtered        water. It is also preferred that said first silver ion generator        be located upstream of said adsorbent filter means.

In another aspect the invention resides broadly in water treatmentapparatus including:

-   -   a mounting base adapted to be secured to a wall for mounting the        apparatus near a water supply outlet;    -   filter means mounted to said mounting base and adapted to be        connected to the water supply outlet, said filter means        including adsorbent filter means for removing undesirable        odours, tastes and chemical pollutants such as chlorine,        trichloromethanes, herbicides, pesticides and the like from the        water and fine filter means in series with said adsorbent filter        means for removing organisms of the protozoan group particularly        amoeba, giardia and cryptospiridium from the water;    -   a first silver ion generator upstream of said adsorbent filter        means and said fine filter means for releasing silver ions into        water inflowing from said water supply outlet;    -   a second silver ion generator downstream of said adsorbent        filter means and said fine filter means for releasing silver        ions into the filtered water;    -   control means for controlling the operation of said first and        second silver ion generators whereby said silver ion generators        discharge silver ions into the water at a predetermined rate and        in response to a predetermined flow rate, said control means        including a flow switch;    -   flow regulating means in series with said adsorbent filter        means, said fine filter means and said first and second dosing        means for regulating the rate of flow of water through said        first and second dosing units;    -   connection means for connecting a power supply to said first and        second dosing means. Advantageously, the second silver ion        generator ensures that sufficient silver ions are available for        destroying any bacteria in drinking vessels or the like into        which the treated water is discharged and also decreases the        possibility of contamination of any pipework or fittings        downstream via back entry. The second silver ion generator is        particularly advantageous with the portable apparatus because of        the likelihood of back contamination in a bush environment.

Preferably, the adsorbent filter means is a carbon filter which isselected to retain therein at least some silver ions. It is believedthat a 5 micron rating is suitable for this purpose. When the firstsilver ion generator is located upstream of the adsorbent filter it isbelieved that at least some of the silver ions become lodged in thecarbon filter thus preventing the growth of harmful bacteria in thefilter.

Preferably, the fine filter means is a ceramic filter which is selectedto prevent the passage of protozoans and undesirable metal particulatessuch as lead. It is believed that a 4 micron rating is suitable. It isalso preferred that the fine filter means be located downstream of saidadsorbent filter means and said dosing means. In this respect it isbelieved that the ceramic filter can be appropriately sized to preventthe passage of pathogenic bacteria for a short period in the event offailure of one or both silver ion generators.

Preferably, the adsorbent filter means and the fine filter means aresuitably sized to provide a reservoir of water which has been dosed withsilver ions so that water will remain in the system for a sufficienttime for all harmful bacteria to be destroyed by the silver ions. In thecase of the portable apparatus it is also preferred that a foot valve ornon-return valve be located upstream of the pump means for preventingbackflow of treated or semi-treated water from the apparatus.

Preferably the flow regulating means is adjustable so as to restrict theflow rate of water through the apparatus so that water remains in theapparatus for a predetermined period greater that the minimum timerequired for destruction of harmful bacteria.

In another aspect the invention resides broadly in a flow switchincluding:

-   -   a body having an inlet passage and an outlet passage;    -   a reed and a contact mounted in said body downstream of said        inlet passage, said reed being adapted for oscillating movement        towards and away from said contact into and out of engagement        therewith, and said reed and said contact being constructed of        electrically conductive material;    -   a piston mounted in said inlet passage for sliding movement        along said inlet passage towards and away from said reed, said        piston having an upstream end and a downstream end, and a flow        passage in said piston, said flow passage having an inlet at or        adjacent the upstream end and an outlet intermediate said        upstream end and said downstream end, the parts being so made        and arranged that fluid entering said inlet passage will cause        said piston to move in said inlet passage and engage with said        reed forcing said reed into electrically conductive engagement        with said contact and will flow through said flow passage and be        discharged sidewardly of said piston in said body downstream of        said inlet passage for discharge through said outlet passage.

Preferably, the piston has a tapered portion adjacent the downstream endand the flow passage outlet is located in the tapered portion.Advantageously, locating the flow passage outlet in this manner ensuresthat flow through the flow passage outlet is not unduly restricted bythe wall of the inlet passage.

Preferably, the body is substantially a rectangular prism in form with asingle cylindrical passage therethrough with one end portion forming theinlet passage and the other end portion forming the outlet passage. Itis also preferred that the cylindrical passage be provided in one halfof the body so that fixing apertures may be provided in the other halfof the body without the risk of opening into the cylindrical passage.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that this invention may be more readily understood and put intopractical effect, reference will now be made to the accompanyingdrawings wherein:

FIG. 1 is a pictorial representation of portable water treatmentapparatus according to the invention;

FIG. 2 is a rear end elevation of the apparatus of FIG. 1;

FIG. 3 is an elevation of one side of the apparatus of FIG. 1 with thecover removed;

FIG. 4 is an elevation of the other side of the apparatus of FIG. 1 withthe cover removed;

FIG. 5 is a schematic representation of the apparatus of FIG. 1;

FIG. 6 is a sectional side elevation of a flow switch according to theinvention as used in the apparatus of FIG. 1.

FIG. 7 is a pictorial representation of water treatment apparatusaccording to the invention for use in an under sink location;

FIG. 8 is a schematic representation of the apparatus of FIG. 7installed under a domestic sink;

FIG. 9 is a pictorial representation of another flow switch according tothe invention which can be used in the apparatus of either FIG. 1 orFIG. 7, with some components in line for assembly;

FIG. 10 is a sectional side elevation of the flow switch of FIG. 9 withthe same components in line for assembly.

DETAILED DESCRIPTION OF THE DRAWINGS

The water treatment apparatus 10 illustrated in FIGS. 1 to 5 has amounting base 11 with an upstanding central partition 12 whichterminates centrally in a handle 13. A cover 14 is attached to the baseby clips 16 on each side of the cover and the handle 13 is accessiblethrough an aperture 17 in the top 18 of the cover. It will be seen thatthe apparatus is a compact unit which can be easily stowed in thestowage compartment of a four wheel drive vehicle or even the boot of acar.

A motor pump unit 21 is mounted to the base 11 and a coarse filter unit22 is connected at one end to the pump inlet 23 and at its other end toa hose 24 which is of a sufficient length to have one end placed in astream or a bucket of water 26 as shown in FIG. 4 for sucking water intothe apparatus for treatment. The primary filter unit 22 is a gauzefilter adapted to remove sand, gravel and other relatively large solids.The hose can be removed from the bucket or the stream after use andcoiled and stowed within the housing adjacent the central partition, thefoot valve 25 being operative to prevent backflow of water from theapparatus.

Two other filter units are mounted downstream of the pump unit, thefirst being a carbon filter 27 mounted to the central partition on oneside and the second being a ceramic filter 28 mounted to the centralpartition on the other side directly opposite the carbon filter. Thesefilters have identical housings and are mounted in the same manner by asecuring plate 29 which is attached to the upper end of the filterhousing and releasably connected to the central partition via bolts 30in key slots 31. The lower ends of the filter housings are restrainedfrom lateral movement by respective collars 32 which extend about thelower ends and are bolted to the base 11. It will be understood thateach filter can be easily serviced by simply lifting the filter housingso that the bolts 30 are released from the key slots 31 whereupon thefilter housing can be simply lifted from the collar 32. It will beappreciated that ease of servicing of the filters is particularlyimportant if operators are to maintain the apparatus in optimumoperating condition. The carbon filter in this embodiment is a fourmicron dolomite ceramic filter with a design flow rate of three litersper minute and the carbon filter is a five micron powdered activatedcarbon impregnated cellulose filter having a design flow rate ofnineteen liters per minute.

A flow control valve 34 is located between the pump outlet 36 and thecarbon filter 27 and is adapted to regulate the flow rate of water fromthe pump. A flow switch 37 and a silver ion generator 38 are locatedbetween the regulating valve and the carbon filter, the flow switchbeing operative to switch the silver ion generator on and off via acontroller 39 which supplies power to the silver ion generator. Thecontroller is connected to a battery by cable 40 and typically thebattery would be in a vehicle and the cable 40 would be connected viathe cigarette lighter socket.

It will be seen that water entering the carbon filter will have beendosed with silver ions which may lodge in the carbon filter and beeffective to prevent the build-up of pathogenic bacteria therein. Anadditional silver ion generator 41 is located immediately downstream ofthe ceramic filter 28 and is arranged to discharge directly into theoutlet pipe 42. The outlet pipe in turn is connected to a finger tipcontrol on/off valve and a discharge spout 43 is connected to the fingertip control outlet valve 44 and is pivotally mounted to the centralpartition so that it can be pivoted about a vertical axis for protectionby the cover 14.

In use, the apparatus is removed from the boot of the car or the stowagecompartment and placed beside the vehicle or even some distance from thevehicle, depending on the length of the cable 40. The cable is thenplugged into the cigarette lighter socket and the hose 24 is loweredinto a water hole, stream, pond or the like or alternatively water canbe collected in the bucket 26 and the hose can be dropped into thebucket. Switch 43 on the controller is then switched on and the pumpshould run to draw water from the bucket and pressurise the system. Oncethe flow switch 37 senses flow, it activates the two silver iongenerators 38 and 41 so that silver ions are discharged into the waterflowing through the system. Once the system is pressurised, a pressureswitch 20 incorporated in the pump switches the pump off and uponrelease of water from the spout 43 the pressure switch restarts thepump. As shown diagramatically in FIG. 5, untreated water enters theapparatus via hose 24 and any solid particles in the water such as sandand gravel are removed by the filter 22 prior to entry of the water tothe pump 21. The rate of flow is regulated by the valve 34 and the waterthen flows through the flow switch 37 and subsequently through the firstsilver ion generator 38. After being dosed with silver ions, the waterenters the carbon filter 27 which should remove odours, tastes andchemical pollutants and then the semi-treated water enters the ceramicfilter 28 which in turn should remove any organisms such as protozoanswhich are not destroyed by the silver ions. The water exiting theceramic filter is then dosed again with silver ions by the silver iongenerator 41 whereupon it is ready for drinking or for bathing. Watercan be obtained by simply operating the finger touch control valve 44.

It will be appreciated that the interconnecting hoses 46, 47 and 48 areall fitted to the relevant components by quick release couplings whichallow quick and easy servicing and replacement of components. It willalso be appreciated that the carbon filter and the ceramic filter aresuitably sized to contain about three liters of water so that at anytime that a traveller requires a drink, the water in the apparatusshould be suitable because it will have been in the system for asufficient length of time to allow the silver ions to destroy anyundesirable bacteria. In this respect it will be understood that theoutlet pipe 42 is selected so that the maximum flow rate allowed is inthe order of only one to two liters per minute. Of course if greaterflow rates are required then additional storage can be added or largercomponents utilised.

The flow switch 37 includes a body 51 having an inlet flow passage 52and an outlet flow passage 53. A reed 54 and a contact bar 55 aremounted in the outlet flow passage with the contact bar being spacedfrom and slightly downstream of the reed with the reed being constructedof a flexible metallic material, in this case stainless spring steel, sothat it can flex towards and away from the contact bar. A piston 56 isslidably mounted in the inlet passage and located so that it can engagewith the reed and force it into electrically conductive engagement withthe contact bar to complete a circuit. A flow passage 57 is providedaxially in the piston extending from its inlet end 58 and opening intothe outlet chamber via a side passage 59. It will be understood that ina no-flow condition the reed forces the piston to a position in whichthe side passage is sheathed within the inlet passage so that only avery small flow or no flow through the inlet passage can occur wherebythe in-flowing water will cause the piston to move towards the outletpassage into engagement with the reed. In this position the side passageopens into the outlet passage and flow through the piston can takeplace. Moreover the reed engages with the contact bar thus forming aconnection between wire 61 and wire 62 while water is flowing. Thepiston initially prevents flow so that it is subject to the full forceof the flowing water and once the piston moves sufficiently to engagethe reed with the contact bar, flow through the piston can occur.

The flow switch 137 illustrated in FIGS. 9 and 10 operates in a similarmanner to flow switch 37 and where appropriate corresponding referencenumerals will be used to reference corresponding components but prefacedby a “1”. The flow switch includes a body 151 which is substantially arectangular prism in form having a flat front face 151 a and a flat rearface 151 b and 2 flat end faces 151 c and 151 d. A cylindrical flowpassage 150 extends through the body from one end to the other providingan inlet flow passage 152 and an outlet flow passage 153. Thecylindrical passage is intersected by another passage 171 which isadapted to screwthreadedly receive a switch assembly 150, shown in linefor assembly. The switch assembly includes a reed 154 and a contact bar155 which extend into the cylindrical flow passage downstream of theinlet flow passage in the same manner as in FIG. 6. The switch isscrewed into position so that the reed is facing upstream and thecontact bar is facing downstream. In this embodiment, the piston 156 hasa conical downstream end portion 174 which terminates in an apex 176which is adapted to make contact with the reed. The flow passage 157extends from the inlet end 158 of the piston and opens into the outletpassage via a side passage 159 which opens approximately midway alongthe conical face of the downstream end portion. It will be appreciatedthat in this form of flow switch, flow is not restricted by the positionof the piston in the inlet flow passage 152 as in the case of the flowcontrol valve of FIG. 6.

The water treatment apparatus 110 illustrated in FIGS. 7 and 8 issimilar to that of FIGS. 1 to 5 in many respects and accordingly whereappropriate corresponding reference numerals have been used to referencecorresponding components but prefaced by a “1”. The apparatus 110 isintended for use with reticulated water systems for example town water,and has a mounting base 111 which has two spaced apart keyholes 161 forsecuring the base to a gable panel of an under-sink cupboard. A singlefiltering housing 163 is mounted to the base and contains a carbonfilter and a ceramic filter with the same filtering specifications as inapparatus 10. The housing together with the enclosed filters can beeasily removed from the base and returned to the factory or otherlocation for servicing. This unit is adapted to be connected directly tothe mains pressure supply pipe 162 via a flow control valve 134 whichalso has a non-return function. It will be appreciated that because ofthe connection to mains water, neither a pump nor a coarse filter isrequired. Furthermore, the controller 139 is connected to mains powervia a twelve volt transformer instead of being connected to the vehiclebattery is in the case of apparatus 10. However, the controller includesa standby battery pack 166 which is arranged to automatically cut in ifmains power fails, thereby ensuring that the silver ion generatorscontinue to work in case of a blackout. The apparatus includes a flowswitch 137 and two silver ion generators which are mounted to the baseand connected in series with the filters in accordance with FIG. 5. Thiscontroller has a plurality of different connections for connection ofthe silver ion generators. It will be appreciated that waterconductivity varies from city to city and thus the power supply to thegenerator needs to be changed to maintain the same quantity of silverions generated in different water supplies. The plurality of differentconnections have been selected to cover a range of water conductivities.

While the foregoing description has been given by way of illustrativeexample of the invention, all other modifications and variations theretoas would be apparent to persons skilled in the art are deemed to fallwithin the broad scope and ambit of this invention as is defined in theappended claims.

1. A flow switch including: a body having an inlet passage and an outlet passage; a reed and a contact mounted in said body downstream of said inlet passage, said reed being adapted for oscillating movement towards and away from said contact into and out of engagement therewith, and said reed and said contact being constructed of electrically conductive material; a piston mounted in said inlet passage for sliding movement along said inlet passage towards and away from said reed, said piston having an upstream end and a downstream end; and a flow passage in said piston, said flow passage having an inlet at or adjacent the upstream end and an outlet intermediate said upstream end and said downstream end, the parts being so made and arranged that fluid entering said inlet passage will cause said piston to move in said inlet passage and engage with said reed forcing said reed into electrically conductive engagement with said contact and will flow through said flow passage and be discharged sidewardly of said piston in said body downstream of said inlet passage for discharge through said outlet passage.
 2. A flow switch according to claim 1, wherein said piston has a tapered portion adjacent said downstream end and said flow passage outlet is located in said tapered portion.
 3. A flow switch according to claim 1, wherein said body is substantially a rectangular prism in form with a single cylindrical passage therethrough with one end portion of said cylindrical passage forming the inlet passage and the other end portion forming the outlet passage.
 4. A flow switch according to claim 1, wherein said body is substantially a rectangular prism in form with a cylindrical passage provided in a portion of the body so that fixing apertures may be provided in the remainder the body without the risk of opening into the cylindrical passage. 